Isoxazolyl indolamines as hypoglycemics

ABSTRACT

This disclosure describes compounds of the formula ##STR1## where R 1  represents hydrogen, fluoro, chloro, lower alkyl having 1 to 4 carbon atoms or lower alkoxy having 1 to 4 carbon atoms, and 
     R 2  and R 3  each independently represent lower alkyl as defined above, or 
     R 2  and R 3  together with N represent ##STR2## wherein n is 1, 2 or 3, and 
     R 4  and R 5  each independently represent hydrogen or lower alkyl as defined above, 
     or a pharmaceutically acceptable acid addition salt thereof, which are useful as anti-diabetic agents in particular as hypoglycemic agents and inhibiting or impeding post-prandial hyperglycemia.

This is a division of application Ser. No. 251,068, filed Apr. 6, 1981,now U.S. Pat. No. 4,336,391.

This invention relates to substituted indolamines which exhibitanti-diabetic activity. In particular, it relates to substitutedisoxazolyl indolamines and pharmaceutically acceptable acid additionsalts.

The compounds of the invention may be represented by the followingstructural formula: ##STR3## wherein

R₁ represents hydrogen, fluoro, chloro, lower alkyl, i.e., alkyl having1 to 4 carbon atoms, e.g., methyl, ethyl, isopropyl and the like, orlower alkoxy, i.e., alkoxy having 1 to 4 carbon atoms, e.g., methoxy,ethoxy, and the like, and

R₂ and R₃ each independently represent lower alkyl as defined above, or

R₂ and R₃ together with N represent ##STR4## wherein

n is 1, 2 or 3, and

R₄ and R₅ each independently represent hydrogen or lower alkyl asdefined above

The compounds of formula (I), are prepared according to the followingreaction scheme: ##STR5## where R₁, R₂, R₃, R₄ and R₅ are as definedabove.

The compounds of formula (I) are prepared by reducing a compound of theformula (II) with a reducing agent such as lithium aluminum hydride, ordiborane, preferably lithium aluminum hydride. The reaction is carriedout in the presence of an inert organic solvent, and although theparticular solvent employed is not critical, the preferred solventsinclude an ether such as diethylether, dioxane or tetrahydrofuran, thelatter being especially preferred. The temperature of the reaction maybe critical, and it is preferred that the reaction be run at atemperature of from about -10° to +10° C., preferably 5° to 8° C. Thereaction is run from about 1 to 7 hours, preferably from about 3 to 5hours. The product is recovered using conventional techniques, e.g.,crystallization.

The compounds of formula (II) are prepared according to the followingreaction scheme: ##STR6## where

n is >3, and

R₁, R₂, R₃, R₄ and R₅ are as defined above.

The compounds of formula (II) are prepared by treating a compound of theformula (III) with a compound of the formula (IV) in the presence of anexcess of paraformaldehyde and an organic solvent. Although theparticular solvent employed is not critical, it is preferred that thereaction be run in the presence of the lower alkanols e.g., methanol,ethanol and the like, preferably ethanol. The temperature of thereaction is not critical but it is preferred that the reaction be run ata temperature of from about 60° to 150° C., preferably the refluxtemperature of the solvent. The reaction is run from about 2 to 35hours, preferably from about 20 to 30 hours. The product may berecovered by conventional techniques e.g., crystallization.

The compounds of formula (III) may be prepared in accordance with thefollowing reaction scheme: ##STR7## where

X is chloro or bromo, and

R₁, R₄ and R₅ are as defined above.

The compounds of formula (III) are prepared by reacting a compound ofthe formula (V) first with silver trifluoromethanesulfonate and thenwith an acetylhalide such as acetylchloride in the presence of anorganic solvent. Although the particular solvent employed is notcritical, the preferred solvents include the halogenated hydrocarbonssuch as methylene chloride, chloroform and the like preferably methylenechloride. The temperature of the reaction is not critical, but it ispreferred that the reaction be run at a temperature of from about 20° to45° C., preferably from about 25° to 35° C. The reaction is run fromabout 2 to 8 hours, preferably from about 3 to 6 hours. The product maybe recovered by conventional techniques e.g., crystallization.

The compounds of formula (V) are prepared in accordance with thefollowing reaction scheme: ##STR8## where R₁, R₄ and R₅ are as definedabove.

The compounds of formula (V) are prepared by cyclizing a compound of theformula (VI) with an acid, such as acetic acid, p-toluenesulfonic acidor polyphosphoric acid, the latter being especially preferred in thepresence of an inert solvent. Although the particular solvent employedis not critical, the preferred solvents include the aromatichydrocarbons such as benzene, toluene and the like, or an excess of theacid utilized above, the latter being especially preferred. Thetemperature of the reaction is not critical, but it is preferred thatthe reaction be run from about 70° to 150° C., preferably from about105° to 120° C. The reaction is run from about 1 to 12 hours, preferablyfrom about 3 to 6 hours. The product is recovered using conventionaltechniques, e.g., filtration.

The compounds of formula (VI) are prepared according to the followingreaction scheme: ##STR9## where R₁, R₅ and R₆ are as defined above.

The compounds of formula (VI) are prepared by treating a compound of theformula (VII) with a compound of the formula (VIII) in the presence ofan inert organic solvent and an acid catalyst such as p-toluenesulfonicacid, polyphosphoric acid or sulfuric acid, preferably p-toluensulfonicacid. The particular solvent employed is not critical, but it ispreferred that the reaction be run in the presence of the loweralkanols, e.g., methanol, ethanol and the like, or the aromatichydrocarbons such as benzene, toluene and the like, preferably, however,ethanol. The temperature of the reaction is not critical, but it ispreferred that the reaction be run from about 0° to 100° C., preferablyfrom about 20° to 35° C. The reaction is run from about 12 to 72 hours,preferably from about 36 to 52 hours. The product is recovered usingconventional techniques, e.g., filtration.

Many of the compounds of formulae (IV), (VII) and (VIII), are known andmay be prepared by methods described in the literature. The compounds offormulae (IV), (VII) and (VIII) not specifically described may beprepared by analogous methods from known starting materials.

It will be understood that the compounds of formula (I) may exist in theform of optically active isomers and can be separated and recovered byconventional techniques, and that such isomeric forms are includedwithin the scope of the invention.

The compounds of formula (I) and (II) and their pharmaceuticallyacceptable salts, are useful because they exhibit pharmacologicalactivity in animals. In particular, the compounds of formula (I) and(II) are useful in the treatment of diabetes as hypoglycemic agents andinhibiting or impeding post-prandial hyperglycemia.

The compounds of formula (I) and (II) are useful in the treatment ofdiabetes as hypoglycemic agents as indicated by the lowering of bloodglucose in 6 to 8 week old male Royal Hart mice weighing 30 to 35 gramswhich are fasted in groups of 5 for 16 hours and then are given aninitial dose of 50 to 200 milligrams per kilogram of animal body weightof the compound orally. Two hours after the test compound isadministered the mice are anesthetized with 85 milligrams per kilogramof animal body weight of sodium hexobarbital and five minutes laterblood is collected via cardiac puncture. The blood samples are placed inan autoanalyzer cup containing 0.025 milliliters of heparin (1,000 unitsper milliliter); and the samples are capped, shaken and stored in ice.The glucose level is determined by the autoanalyzer potassium ferriccyanide N-2b method and these glucose levels are then compared with theglucose levels of the control group which receives orally 0.5%carboxymethyl cellulose and is run concurrently. To validate thisexperiment, a known hypoglycemic standard is included each time the testis run.

The compounds of formula (I) and (II) are also useful in treatment ofdiabetes by inhibiting or impeding post-prandial hyperglycemia asindicated by a lowering of the blood sugar levels in male Wistar ratsafter an oral starch load. In this test male Wistar rats in groups of 5which are fasted for 16 hours are given an initial dose of from 25 to200 mg/kg p.o. of the test compound. One hour later the rats are given1.0 grams per kilogram of animal body weight of cooked starch load.Thirty minutes after administration of the starch, the rats areanesthetized with 120 milligrams per kilogram of animal body weight ofsodium hexobarbital after which blood is collected via cardiac puncture.The blood samples are placed in an autoanalyzer cup containing 0.1milliliters of heparin (1,000 units per milliliters). The heparinizedblood is used to determine the blood sugar level with an autoanalyzer.The blood sugar content is compared to the control group which receives0.5% carboxymethyl cellulose and an oral starch load and are runconcurrently.

For both the hypoglycemic and inhibiting post-prandial hyperglycemiause, the compounds of formula (I) and (II) and their non-toxic,pharmaceutically acceptable salts may be administered orally orparenterally as such or admixed with conventional pharmaceuticalcarriers. They may be administered orally in such forms as tablets,dispersible powders, granules, capsules, syrups and elixirs, andparenterally as solutions, e.g., a sterile injectable aqueous solution.The compositions for oral use may contain one or more conventionaladjuvants, such as sweetening agents, flavoring agents, coloring agentsand preserving agents, in order to provide an elegant and palatablepreparation. Tablets may contain the active ingredient in admixture withconventional pharmaceutically acceptable excipients, e.g., inertdiluents, such as calcium carbonate, sodium carbonate, lactose, andtalc, granulating and disintegrating agents, e.g., starch and andalginic acid, binding agents, e.g., magnesium stearate, stearic acid andtalc. The tablets may be coated by known techniques to delaydisintegration and absorption in the gastro-intestinal tract and therebyprovide a sustained action over a longer period. Similarly, suspensions,syrups and elixirs may contain the active ingredient in admixture withany of the conventional excipients utilized in the preparation of suchcompositions, e.g., suspending agents such as methylcellulose,tragacanth and sodium alginate; wetting agents such as lecithin,polyoxyethylene stearate and polyoxyethylene sorbitan monooleate; andpreservatives such as ethyl p-hydroxybenzoate. Capsules may contain theactive ingredient alone or admixed with an inert solid diluent, e.g.,calcium carbonate, calcium phosphate and kaolin. The injectablecompositions are formulated as known in the art. These pharmaceuticalpreparations may contain up to about 90% of the active ingredient incombination with the carrier or adjuvant.

The hypoglycemic effective amount of active ingredient employed in thetreatment of diabetes may vary depending on the particular compoundemployed, the mode of administration and the severity of the conditionbeing treated. However, in general satisfactory results in the treatmentof diabetes are obtained when a compound of formula (I) or a compound ofthe formula (II) is administered at a daily dosage of from about 5milligrams to about 800 milligrams per kilogram of animal body weight,preferably given orally and in divided doses two to four times a day, orin sustained release form. For most large mammals, the total dailydosage is from about 70 milligrams to about 1000 milligrams. Unit dosageforms suitable for internal use comprise from about 17.5 milligrams toabout 1000 milligrams, more usually 17.5 to 500 milligrams, of theactive compound in intimate admixture with a solid or liquid,pharmaceutically acceptable carrier.

The effective amount of active ingredient for inhibiting post-prandialhyperglycemia employed in the treatment of diabetes may vary dependingon the particular compound employed, the mode of administration and theseverity of the condition being treated. However, in generalsatisfactory results in the treatment of diabetes are obtained when acompound of formula (I), or a compound of the formula (II), isadministered at a daily dosage of from about 5 milligrams to about 80milligrams per kilogram of animal body weight, preferably given orallyand in divided doses two to four times a day, or in sustained releaseform. For most large mammals, the total daily dosage is from about 25milligrams to about 1000 milligrams, preferably given at mealtime asconventional in treatments with substances having such activity, e.g.,three times a day, particularly before a carbohydrate-rich meal.

The compounds of formula (I) and (II) may be similarly administered inthe form of their non-toxic pharmaceutically acceptable acid additionsalts. Such salts possess the same order of activity as the free baseand are readily prepated by reacting the compound with apharmaceutically acceptable acid by conventional techniques, andaccordingly are included within the scope of this invention.Representative of the inorganic salts are the hydrochloride,hydrobromide, hydroiodide, phosphate (including hydrogen phosphate),metaphosphate, and sulfate (including hydrogen sulfate). Representativeexamples of the organic salts are the acetate, maleate, fumarate and thelike.

Tablets and capsules containing the ingredients indicated below may beprepared by conventional techniques and are useful in treating diabetes,at a dose of one tablet or capsule, 2 to 4 times a day.

    ______________________________________                                                           Weight (mg.)                                               Ingredients          tablet    capsule                                        ______________________________________                                        3-dimethylamino-1-[2-(3-ethyl-5-                                              methyl-4-isoxazolyl)-1H-indol-3-yl]-                                          1-propanol           200       200                                            tragacanth           10        --                                             lactose              247.5     300                                            corn starch          25        --                                             talcum               15        --                                             magnesium stearate   2.5       --                                             Total                500       500                                            ______________________________________                                    

EXAMPLE 1 1-(3-ethyl-5-methyl-4-isoxazolyl)-1-ethanone phenyl hydrazone

A mixture of 61.1 g. (0.4 mole) of 4-acetyl-3-ethyl-5-methyl-isoxazole,39.4 ml. (0.4 mole) of phenyl hydrazine and 500 mg. toluenesulfonic acidin 400 ml. ethanol is stirred at room temperature for 48 hours. Theresulting solid is filtered and washed with cold ether to give1-(3-ethyl-5-methyl-4-isoxazolyl)-1-ethanone phenyl hydrazone; m.p. 72°to 75° C.

Following the above procedure and using in place of4-acetyl-3-ethyl-5-methyl isoxazole an equivalent amount of

(a) 4-acetyl-3-ethyl-isoxazole

(b) 4-acetyl-5-methyl-isoxazole

(c) 4-acetyl-3,5-dimethyl-isoxazole

there is obtained

(a) 1-(3-ethyl-4-isoxazolyl)-1-ethanone phenyl hydrazone

(b) 1-(5-methyl-4-isoxazolyl)-1-ethanone phenyl hydrazone, or

(c) 1-(3,5-dimethyl-4-isoxazolyl)-1-ethanone phenyl hydrazone.

Again, following the above procedure and using in place of phenylhydrazine an equivalent amount of

(d) p-fluorophenyl hydrazine

there is obtained

(d) 1-(3-ethyl-5-methyl-4-isoxazolyl)-1-ethanone-p-fluorophenylhydrazone.

Again, following the procedure set out in Example I and using in placeof 4-acetyl-3-ethyl-5-methyl-isoxazole an equivalent amount of4-acetyl-3,5-dimethyl-isoxazole; and using in place of phenyl hydrazinean equivalent amount of p-fluorophenyl hydrazine there is obtained

(e) 1-(3,5-dimethyl-4-isoxazolyl)-1-ethanone-p-fluorophenyl hydrazone.

EXAMPLE 2 2-(3-ethyl-5-methyl-4-isoxazolyl)-indole

To 1350 grams of polyphosphoric acid at 100° to 110° C. there is addedportionwise 74.5 g. (0.307 mole) of1-(3-ethyl-5-methyl-4-isoxazolyl)-1-ethanone phenyl hydrazone whilemaintaining the temperature between 105° C. and 115° C. After additionis complete, the mixture is stirred at 100° to 110° C. for 3 hours. Themixture is then poured onto ice and water and the resulting gumextracted into methylene chloride. The methylene chloride isdecolorized, dried over anhydrous magnesium sulfate, filtered andevaporated in vacuo to give 2-(3-ethyl-5-methyl-4-isoxazolyl)-indole.

Following the above procedure and using in place of1-(3-ethyl-5-methyl-4-isoxazolyl)-1-ethanone phenyl hydrazone anequivalent amount of

(a) 1-(3-ethyl-4-isoxazolyl)-1-ethanone phenyl hydrazone

(b) 1-(5-methyl-4-isoxazolyl)-1-ethanone phenyl hydrazone

(c) 1-(3,5-dimethyl-4-isoxazolyl)-1-ethanone phenyl hydrazone

(d) 1-(3-ethyl-5-methyl-4-isoxazolyl)-1-ethanon-p-fluorophenylhydrazone, or

(e) 1-(3,5-dimethyl-4-isoxazolyl)-1-ethanone-p-fluorophenyl hydrazone

there is obtained

(a) 2-(3-ethyl-4-isoxazolyl)-indole,

(b) 2-(5-methyl-4-isoxazolyl)-indole,

(c) 2-(3,5-dimethyl-4-isoxazolyl)-indole

(d) 5-fluoro-2-(3-ethyl-5-methyl-4-isoxazolyl)-indole, or

(e) 5-fluoro-2-(3,5-dimethyl-4-isoxazolyl)-indole respectively.

EXAMPLE 3 2-(3-ethyl-5-methyl-4-isoxazolyl)-3-acetyl indole [CompoundIII]

A solution of 33.5 g. (0.148 mole) of2-(3-ethyl-5-methyl-4-isoxazolyl)-indole in 450 ml. methylene chlorideis treated by the portionwise addition of 41.8 g. (0.163 mole) of silvertrifluoromethanesulfonate. The resulting suspension is then treated bythe dropwise addition of 12.8 g. (0.163 mole) of acetyl chloride in 50ml. methylene chloride. The temperature rises to 35° C. during theaddition. After the addition is complete the mixture is stirred at roomtemperature for 4 hours and then filtered. The filtrate is washed with150 ml. 2 N sodium hydroxide, water and 2 N sodium hydroxide dried overanhydrous magnesium sulfate and evaporated in vacuo to give an oil. Theoil is crystallized from ether to give2-(3-ethyl-5-methyl-4-isoxazolyl)-3-acetyl indole, m.p. 170°-173° C.

Following the above procedure and using in place of2-(3-ethyl-5-methyl-4-isoxazolyl)indole an equivalent amount of

(a) 2-(3-ethyl-4-isoxazolyl)-indole,

(b) 2-(5-methyl-4-isoxazolyl)-indole,

(c) 2-(3,5-dimethyl-4-isoxazolyl)-indole

(d) 5-fluoro-2-(3-ethyl-5-methyl-4-isoxazolyl)-indole, or

(e) 5-fluoro-2-(3,5-dimethyl-4-isoxazolyl)-indole

there is obtained

(a) 2-(3-ethyl-4-isoxazolyl)-3-acetyl indole,

(b) 2-(5-methyl-4-isoxazolyl)-3-acetyl indole,

(c) 2-(3,5-dimethyl-4-isoxazolyl)-3-acetyl indole,

(d) 5-fluoro-2-(3-ethyl-5-methyl-4-isoxazolyl)-3-acetyl indole, or

(e) 5-fluoro-2-(3,5-dimethyl-4-isoxazolyl)-3-acetyl indole respectively.

EXAMPLE 43-dimethylamino-1-[2-(3-ethyl-5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propane[Compounds II]

A mixture of 12 g. (0.045 mole) of2-(3-ethyl-5-methyl-4-isoxazolyl)-3-acetyl indole, 4 g. (0.049 mole) ofdimethylamine hydrochloride, and 0.5 ml. concentrated hydrochloric acidin 70 ml. of ethanol is heated to reflux and treated by the portionwiseaddition of 14 g. (0.470 mole) of paraformaldehyde over 5 hours. Theresulting mixture is refluxed an additional 24 hours, cooled andevaporated in vacuo. The residue is then dissolved in 300 ml. methylenechloride and washed with 200 ml. 2 N hydrochloric acid, the aqueous acidis cooled and made basic with 2 N sodium hydroxide and extracted withmethylene chloride. The organic layer is dried over anhydrous magnesiumsulfate, filtered and evaporated in vacuo. The residue is crystallizedfrom ether to give3-dimethylamino-1-[2-(3-ethyl-5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanone,m.p. 146°-148° C.

Following the above procedure and using in place of2-(3-ethyl-5-methyl-4-isoxazolyl)-3-acetyl indole an equivalent amountof

(a) 2-(3-ethyl-4-isoxazolyl)-3-acetyl indole,

(b) 2-(5-methyl-4-isoxazolyl)-3-acetyl indole,

(c) 2-(3,5-dimethyl-4-isoxazolyl)-3-acetyl indole,

(d) 5-fluoro-2-(3-ethyl-5-methyl-4-isoxazolyl)-3-acetyl indole, or

(e) 5-fluoro-2-(3,5-dimethyl-4-isoxazolyl)-3-acetyl indole

there is obtained

(a)3-dimethylamino-1-[2-(3-ethyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanone

(b)3-dimethylamino-1-[2-(5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanone

(c)3-dimethylamino-1-[2-(3,5-dimethyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanon

(d)3-dimethylamino-1-[5-fluoro-2-(3-ethyl-5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanone,or

(e)3-dimethylamino-1-[5-fluoro-2-(3,5-dimethyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanonerespectively.

Also following the above procedure and using in place of dimethylaminean equivalent amount of

(f) pyrrolidine

there is obtained

(f)3-pyrrolidino-1-[2-(3-ethyl-5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanone.

The title compound of Example 4 has an ED₂₅ of 63.0 mg/kg in mice as ahypoglycemic agent.

EXAMPLE 53-dimethylamino-1-[2-(3-ethyl-5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanol[Compounds I]

A suspension of 816 mg. (0.022 mole) of lithium aluminum hydride in 125ml. tetrahydrofuran is cooled to 5° and treated by the dropwise additionof 3.5 g. (0.011 mole) of3-dimethylamino-1-[2-(3-ethyl-5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanonein 125 ml. tetrahydrofuran maintaining the temperature between 5°-8° C.The resulting mixture is then stirred for 4 hours at 0°-5°, then cooledto -50° and quenched by the addition of 10 ml. saturated magnesiumsulfate solution. The mixture is warmed to room temperature and filteredand the filtrate is evaporated in vacuo. The resulting residue isdissolved in methylene chloride, washed with water, dried over magnesiumsulfate, filtered and evaporated in vacuo. The residue is crystallizedfrom ether to give3-dimethylamino-1-[2-(3-ethyl-5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanol,m.p. 166°-169° C.

Following the above procedure and using in place of3-dimethylamino-1-[2-(3-ethyl-5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanonean equivalent amount of

(a)3-dimethylamino-1-[2-(3-ethyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanone

(b)3-dimethylamino-1-[2-(5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanone

(c)3-dimethylamino-1-[2-(3,5-dimethyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanone

(d)3-dimethylamino-1-[5-fluoro-2-(3-ethyl-5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanone

(e)3-dimethylamino-1-[5-fluoro-2-(3,5-dimethyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanone,or

(f)3-pyrrolidino-1-[2-(3-ethyl-5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanone

there is obtained

(a)3-dimethylamino-1-[2-(3-ethyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanol

(b)3-dimethylamino-1-[2-(5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanol

(c)3-dimethylamino-1-[2-(3,5-dimethyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanol

(d)3-dimethylamino-1-[5-fluoro-2-(3-ethyl-5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanol

(e)3-dimethylamino-1-[5-fluoro-2-(3,5-dimethyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanol,or

(f)3-pyrrolidino-1-[2-(3-ethyl-5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanol.

The title compound of Example 5 has an ED₂₅ of 83.0 mg/kg in mice as ahypoglycemic agent.

What is claimed is:
 1. A pharmaceutical composition useful in treatingdiabetes as a hypoglycemic agent comprising a compound of the formula:##STR10## or of the formula ##STR11## wherein R₁ represents hydrogen,fluoro, chloro, lower alkyl having 1 to 4 carbon atoms, or lower alkoxyhaving 1 to 4 carbon atoms,R₂ and R₃ each independently represent loweralkyl having 1 to 4 carbon atoms, or R₂ and R₃ together with N represent##STR12## wherein n is 1, 2 or 3, and R₄ and R₅ each independentlyrepresent hydrogen or lower alkyl having 1 to 4 carbon atoms,or apharmaceutically acceptable acid addition salt thereof in associationwith a pharmaceutical carrier or diluent, said compound being present inan amount sufficient to provide a daily dose of 70 to 1000 milligrams ofcompound.
 2. A pharmaceutical composition according to claim 1comprising 17.5 to 1000 milligrams per unit dosage.
 3. A pharmaceuticalcomposition according to claim 1 comprising 17.5 to 500 milligrams perunit dosage.
 4. A pharmaceutical composition according to claim 1 inwhich the compound is3-dimethylamino-1-[2-(3-ethyl-5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanolor a pharmaceutically acceptable acid addition salt thereof.
 5. Apharmaceutical composition according to claim 1 in which the compound is3-dimethylamino-1-[2-(3-ethyl-5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanoneor a pharmaceutically acceptable acid addition salt thereof.
 6. Apharmaceutical composition useful in treating diabetes by inhibitingpost-prandial hyperglycemia comprising a compound of the formula##STR13## or the formula ##STR14## wherein R₁ represents hydrogen,fluoro, chloro, lower alkyl having 1 to 4 carbon atoms, or lower alkoxyhaving 1 to 4 carbon atoms,R₂ and R₃ each independently represent loweralkyl having 1 to 4 carbon atoms, or R₂ and R₃ together with N represent##STR15## wherein n is 1, 2 or 3, and R₄ and R₅ each independentlyrepresent hydrogen or lower alkyl having 1 to 4 carbon atoms,or apharmaceutically acceptable acid addition salt thereof in associationwith a pharmaceutical carrier or diluent, said compound being present inan amount sufficient to provide a daily dose of 25 to 1000 milligrams ofcompound.
 7. A pharmaceutical composition according to claim 6 in unitsdosage form for administration 3 times a day.
 8. A pharmaceuticalcomposition according to claim 6 in which the compound is3-dimethylamino-1-[2-(3-ethyl-5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanolor a pharmaceutically acceptable acid addition salt thereof.
 9. Apharmaceutical composition according to claim 6 in which the compound is3-dimethylamino-1-[2-(3-ethyl-5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanoneor a pharmaceutically acceptable acid addition salt thereof.
 10. Amethod of treating diabetes in mammals which comprises administering toa mammal in need of such treatment an anti-diabetes effective amount ofa compound of the formula ##STR16## or the formula ##STR17## wherein R₁represents hydrogen, fluoro, chloro, lower alkyl having 1 to 4 carbonatoms, or lower alkoxy having 1 to 4 carbon atoms,R₂ and R₃ eachindependently represent lower alkyl having 1 to 4 carbon atoms, or R₂and R₃ together with N represent ##STR18## wherein n is 1, 2 or 3, andR₄ and R₅ each independently represent hydrogen or lower alkyl having 1to 4 carbon atoms,or a pharmaceutically acceptable acid addition saltthereof.
 11. A method according to claim 10 in which 70 to 1000milligrams of the compound is administered daily as a hypoglycemicagent.
 12. A method according to claim 11 in which 17.5 to 1000milligrams of the compound is administered per unit dose.
 13. A methodaccording to claim 11 in which 17.5 to 500 milligrams of the compound isadministered per unit dose.
 14. A method according to claim 11 in whichthe compound is3-dimethylamino-1-[2-(3-ethyl-5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanolor a pharmaceutically acceptable acid addition salt thereof.
 15. Amethod according to claim 11 in which the compound is3-dimethylamino-1-[2-(3-ethyl-5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanoneor a pharmaceutically acceptable acid addition salt thereof.
 16. Amethod according to claim 10 in which 25 to 1000 milligrams of thecompound is administered daily to inhibit post-prandial hyperglycemia.17. A method according to claim 16 in which the compound is administeredin unit dosage form three times a day.
 18. A method according to claim16 in which the compound is3-dimethylamino-1-[2-(3-ethyl-5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanolor a pharmaceutically acceptable acid addition salt thereof.
 19. Amethod according to claim 16 in which the compound is3-dimethylamino-1-[2-(3-ethyl-5-methyl-4-isoxazolyl)-1H-indol-3-yl]-1-propanoneor a pharmaceutically acceptable acid addition salt thereof.